Keyboard percussion instrument



May 13, 1 969 YOICHI HIRAOKA v KEYBOARD PERCUSSION INSTRUMENT Filed Jan. 11, 1968 FIG! INVENTOR. YOICHI HIRAOKA ATTORNEYS United States Patent 3,443,469 KEYBOARD PERCUSSION INSTRUMENT Yoichi Hiraoka, 6 Andover Court, Garden City, NY. 11530 Filed Jan. 11, 1968, Ser. No. 697,183 Int. Cl. Gd 13/08 US. Cl. 84-410 7 Claims ABSTRACT OF THE DISCLOSURE This invention relates to keyboard percussion instruments such as the Xylophone and particularly to improvements in the structure and mounting of resonance tubes therefor.

A suggestion has already been made, in Japanese Patent 9641 published May 21, 1963, to mount the resonance tubes of a Xylophone horizontally instead of vertically. This has the advantage of making the instrument more compact and, therefore, portable, and of making it playable from a table top instead of necessarily being supported by its own legs to allow space for vertically hanging resonance tubes.

I have now found that the projection and quality of tones from the instrument toward the audience can be improved significantly by supporting the forward and rearward ends of the resonance tubes in opposed pairs of lateral frame members supporting the keys or tone bars. The tubes have open ends facing the audience, openings in their upper portions opposite and directly under the keys, and baffies rearwardly of the upper openings at varying distances depending upon the tone to be resonated.

The structure and novel features of the keyboard percussion instrument of my invention, as well as the advantages thereof, will become more apparent from the following detailed description made with reference to 'the accompanying drawing of a portable Xylophone wherein:

FIGURE 1 is a view in elevation;

FIGURE 2 is a plan view; and

FIGURE 3 is view in cross-section taken on section 3 of FIGURE 2.

The Xylophone illustrated by 'way of example in the drawing compirses longitudinal side boards or frame members 1 and 2 and pairs of lateral or transverse frame members 4, 6 and 7, 9. Each pair of lateral frame members supports a keyboard of keys 10 suspended over felt pads 11 and held in place by cords 12 passing through transverse holes 14 in the keys 10 and eyelets 16 in the frame between the keys, the ends of each cord 12 being tied together or maintained under tension by a spring as shown at 17.

Resonance tubes 20 are supported at the forward ends 21 and rearward ends 22 in the frame members 4 and 6 or 7 and 9, respectively. Each resonance tube 20 is provided with an upper opening 24 and a bafile 26, the forward end 21 being open, and each resonance tube being disposed immediately beneath and in alignment with a given key.

Investigations have revealed that, when an instrumentalist strikes a key 10 with a hammer, the sonic vibration set 3,443,469 Patented May 13, 1969 up in the key is transmited into the interior of the resonance tube 20, in significant part at least through the upper opening 24, wherein it is amplified by resonance and projected forwardly through the opening at the forward end 21 of the tube with the cooperation of the bafile 26 for reflecting the vibrations toward the open end and the audience. The distance between the upper opening 24 and the bafiie 26 of a given resonance tube 20 depends upon the tone or frequency of vibrations of the key 10 beneath which the tube is positioned, being greater with decreasing frequency and lower tone. Optimum tonal quality and projection appears to be achieved when the bafiles 26, if projected on a horizontal planes, describe an arc A or B, as shown in dot dash lines in FIGURE 2, having a center of curvature behind the instrument, the upper openings 24 are equidistant from the forward ends of the tubes and have a diameter between one-half and three-quarters the inside diameter of the tube. The upper opening in the tube is spaced away from and forward of the battle.

I claim:

1. A keyboard percussion instrument having side boards and opposed lateral frame members, a row of keys supported 0n the opposed frame members, and resonance tubes under the keys, each tube having a baffie, an open forward end and an upper opening under a given key, wherein the forward and rearward ends of the tubes are supported in opposed frame members.

2. A keyboard percussion instrument as defined in claim 1 wherein a line through the bafiles in a row of resonance tubes describes an are having a center of curvature behind the instrument.

3. A keyboard percussion instrument as defined in claim 1 wherein the upper openings in the tubes are equidistant from the open forward ends thereof.

4. A keyboard percussion instrument as defined in claim 1 wherein the upper openings in the tubes have a diameter between about one-half and three-quarters the inside diameter of the tubes.

5. A keyboard percussion instrument as defined in claim 1 wherein the upper opening in the tube is spaced away from and forward of the baffle.

6. A keyboard percussion instrument as defined in claim 1 wherein the forward and rearward ends of the tubes in a row of tubes terminate in receptive openings therefor in said frame members.

7. A resonance tube for a key in a keyboard percussion instrument having a pair of lateral frame member-s supporting a row of keys thereover, said resonance bar being mounted below said key in and between said frame members and terminating therein, and having an open forward end, a bafile for reflecting sonar vibrations toward and out the open forward end, and an opening in the upper surface and forward of the baffle for receiving sonor vibrations from said key.

References Cited UNITED STATES PATENTS 1,283,774 11/1918 Hope-Jones 84403 1,595,359 8/1926- Schlater 84410 1,620,869 3/1927 Cabot 8441O 2,534,417 12/1950 DargiS 84-410 RICHARD B. WILKINSON, Primary Examiner.

LAWRENCE R. FRANKLIN, Assistant Examiner.

US. Cl. X.R. 

